The Digital Filter Block (DFB) of PSoC 3/5 includes a multiply and accumulate engine which can be used to speed up mathematical computations. MAC contains a 24-by-24 bit multiplier, and a 48-bit adder, which can perform fractional multiply-accumulate, and multiply operations in one cycle. There are two staging registers and two holding registers associated with DFB input and output respectively. The two inputs values for MAC calculation can be passed through staging registers, and the 24-bit output can be read from one of the holding registers.
PSoC Creator currently does not support custom algorithm development using DFB. Please contact Cypress technical support if you need to use DFB for MAC operation.